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Visitor,
Welcome to our web photovoltaic laboratory of
University Defence in the Czech Republic. We wish you liked my pages and
returned back again.
a)
Introduction
b)
Photovoltaic
laboratory
c)
Experimental results
c) References
a) Introduction
The solar
technology is one of the fastest developing renewable technologies. "It
has been over 150 years since Besquerel in 1839 first discovered that
a photo voltage was developed when light was directed onto one of the
electrodes in an electrolyte solution. Adams and Day were the first to
observe the photovoltaic effect in a solid (selenium) in 1877 .
However, it was not until 1954 that literature published results on
the use of photovoltaic effect in energy conversion processes. " [1].
The main components of solar generator system, including photovoltaic
arrays, power electronics, DC or AC loads and storage batteries, are
illustrated in figure 1a. PV arrays often combine as many (PV)
cells in series to produce voltages in the range of 10 to 30 V at the
power generation of approximate 50W and currents of several amperes.
The PV modules were divided into series connections (called a string),
each generating a high voltage (approximately 150 - 300 V). These
series connections were then connected in parallel, in order to reach
high power levels. These series connections were then connected in
parallel, through string diodes. If the loads are AC, an inverter can
be incorporated into the system to convert the DC from the PV
arrays to AC. Most good inverters are capable of operating at
conversion efficiency higher than 90% over of their output power range.
Grid-connected PV systems connect the output of the PV inverter
directly to the utility grid and thus capable of supplying power to
the utility grid (see Fig. 1c).
a) [2]
b)
[2] 
c)[6]
This PVM
topology includes some several limitation, such as power losses due to
string diodes, extra losses between the PV modules and lower
efficiency due to a centralized maximum power point tracking (MPPT),
nonflexible a system design during time when owner want to extend a
total power of photovoltaic sources. The more efficient technology,
where several strings are interfaced with own dc-dc converter and then
connected in parallel, can be seen in Fig. 1b. This string topology (called
a Multi-string) can be beneficial, compared with the centralized
system, since every string can be controlled individually and maximum
power point tracking can be applied individually. Flexible design with
higher efficiency is hereby achieved. On the other hand the separate
dc-dc modules compared with the centralized dc-dc module leads to
higher cost and higher retail prices. [2]
b)
Photovoltaic
laboratory [8]
The
experimental test bench is shown in Fig. 2.
The main components of solar our generator system, including:
1)
Photovoltaic arrays (Schüco MPE 205 PS 05) 
[4]
Electrical and
mechanical specifications:
- Maximal power = 205 Wp
- Tolerance on maximal
power = +5%
- Module efficiency (%) =
13.7%; Cell efficiency = 15.6%
- Number of rows = 54
(6x9);
-
- Nominal voltage =
27 V; Open voltage a module = 32.9 V
- Nominal current = 7.6 A;
Short current = 8.35 A
-
- Shipping Weight = 18 kg
- Dimensions (l x w x d) =
1495x1001x42 mm
2)
Power electronics (dc-ac) (Sunny Boy 1100)
[6]
Input (DC)
- Maximal DC power = 1210
W
- Maximal DC voltage = 400
V
- PV voltage range (MPPT)
= 139-320 V
- Maximal input current =
10 A
Output (AC)
- Nominal AC output = 1000
W
- Nominal AC voltage =
220-240 V
- Maximal output current =
5.6 A
- AC grid frequency = 50
Hz (4.5 Hz)
- Single phase
- Efficiency = 92%
c)
Experimental results
e.g.
17.05.2010
a) Power and Total
yield
b) Input DC and output AC (V, I) of inverter
a)
b)
06:30
9°C 
;
07:30 9°C
;
08:30 9°C
;
9:30 8 °C
;
10:30 9 °C
;
11:30 9°C
; 12:30
10°C ;
13:30 10°C
; 14:30 11°C
; 15:30 11 °C
;
16:30 10 °C
;
17:30 9°C
;
18:30 10°C
[7]
more
details can be found below
and whether
on the page [7]
1. Introduction
2. Power and Total
yield {Month, day}
3. Output DC (V, I) of PV
{day}
4. Input DC and output AC (V,
I) of inverter {hour}
5. Specific
plant yield (kWh/kWp)
d) References
[1] F.
Lasnier, T.G. Ang, Photovoltaic Engineering Handbook, Published under
the Adam Hilger, ISBN: 0-85274-311-4.
[2] S.B. Kjaer,
J. K. Pedersen, F. Blaabjerg, A Review of Single-Phase Grid-Connected
Inverters for Photovoltaic Modules, IEEE Transaction on Industry
Applications, Vol. 41, No. 5, 2005.
[3] F.
Chimento, S. Musumeci, A. Raciti, C.A. Sapuppo, A Control Algorithm
for Power Converter in the Field of Photovoltaic Application, In EPE
Conference (
Aalborg), 2007, ISBN: 9789075815108.
[4] http://www.schueco.com
[5] http://files.gsenergy.webnode.cz/200000037-518eb52890/tabulky%20schuco.pdf
[6] http://www.sma.de/en.html
[7] http://freemeteo.com/default.asp?la=1&pid=20&gid=3078610
[8] 
Acknowledgment
The
research work is supported by the GA of the
Czech
Republic
(project no. 102/09/0013).
E-mail: jan.leuchter@unob.cz
Tel: +420 973 443660
poslední aktualizace: 25.1.2010